Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 291
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 149(6): 1221-32, 2012 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-22682245

RESUMO

When replication forks stall at damaged bases or upon nucleotide depletion, the intra-S phase checkpoint ensures they are stabilized and can restart. In intra-S checkpoint-deficient budding yeast, stalling forks collapse, and ∼10% form pathogenic chicken foot structures, contributing to incomplete replication and cell death (Lopes et al., 2001; Sogo et al., 2002; Tercero and Diffley, 2001). Using fission yeast, we report that the Cds1(Chk2) effector kinase targets Dna2 on S220 to regulate, both in vivo and in vitro, Dna2 association with stalled replication forks in chromatin. We demonstrate that Dna2-S220 phosphorylation and the nuclease activity of Dna2 are required to prevent fork reversal. Consistent with this, Dna2 can efficiently cleave obligate precursors of fork regression-regressed leading or lagging strands-on model replication forks. We propose that Dna2 cleavage of regressed nascent strands prevents fork reversal and thus stabilizes stalled forks to maintain genome stability during replication stress.


Assuntos
Replicação do DNA , Endonucleases Flap/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/citologia , Schizosaccharomyces/metabolismo , Quinase do Ponto de Checagem 2 , Epistasia Genética , Instabilidade Genômica , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Schizosaccharomyces/genética
2.
Mol Psychiatry ; 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39187625

RESUMO

Recent studies have provided promising evidence that neuroimaging data can predict treatment outcomes for patients with major depressive disorder (MDD). As most of these studies had small sample sizes, a meta-analysis is warranted to identify the most robust findings and imaging modalities, and to compare predictive outcomes obtained in magnetic resonance imaging (MRI) and studies using clinical and demographic features. We conducted a literature search from database inception to July 22, 2023, to identify studies using pretreatment clinical or brain MRI features to predict treatment outcomes in patients with MDD. Two meta-analyses were conducted on clinical and MRI studies, respectively. The meta-regression was employed to explore the effects of covariates and compare the predictive performance between clinical and MRI groups, as well as across MRI modalities and intervention subgroups. Meta-analysis of 13 clinical studies yielded an area under the curve (AUC) of 0.73, while in 44 MRI studies, the AUC was 0.89. MRI studies showed a higher sensitivity than clinical studies (0.78 vs. 0.62, Z = 3.42, P = 0.001). In MRI studies, resting-state functional MRI (rsfMRI) exhibited a higher specificity than task-based fMRI (tbfMRI) (0.79 vs. 0.69, Z = -2.86, P = 0.004). No significant differences in predictive performance were found between structural and functional MRI, nor between different interventions. Of note, predictive MRI features for treatment outcomes in studies using antidepressants were predominantly located in the limbic and default mode networks, while studies of electroconvulsive therapy (ECT) were restricted mainly to the limbic network. Our findings suggest a promise for pretreatment brain MRI features to predict MDD treatment outcomes, outperforming clinical features. While tasks in tbfMRI studies differed, those studies overall had less predictive utility than rsfMRI data. Overlapping but distinct network-level measures predicted antidepressants and ECT outcomes. Future studies are needed to predict outcomes using multiple MRI features, and to clarify whether imaging features predict outcomes generally or differ depending on treatments.

3.
Circ Res ; 132(9): e134-e150, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-36999436

RESUMO

BACKGROUND: IL-37 (interleukin-37), a natural suppressor of innate inflammatory and immune responses, is increased in patients with myocardial infarction. Platelets play an important role in the progress of myocardial infarction, but the direct effects of IL-37 on platelet activation and thrombosis, as well as the underlying mechanisms, still remain unclear. METHODS: We evaluated the direct effects of IL-37 on agonists-induced platelet activation and thrombus formation, as well as revealed the underlying mechanisms using platelet-specific IL-1R8 (IL-1 receptor 8)-deficient mice. Using myocardial infarct model, we explored the effects of IL-37 on microvascular obstruction and myocardial injury. RESULTS: IL-37 directly inhibited agonists-induced platelet aggregation, dense granule ATP release, P-selectin exposure, integrin αIIbß3 activation, platelet spreading, and clot retraction. IL-37 inhibited thrombus formation in vivo in a FeCl3-injured mesenteric arteriole thrombosis mouse model and ex vivo in a microfluidic whole-blood perfusion assay. Mechanistic studies using platelet-specific IL-1R8-deficient mice revealed that IL-37 bound to platelet IL-1R8 and IL-18Rα, and IL-1R8 deficiency impaired the inhibitory effects of IL-37 on platelet activation. Using PTEN (phosphatase and tensin homolog)-specific inhibitor and PTEN-deficient platelets, we found that IL-37 combined with IL-1R8 to enhance PTEN activity, inhibit Akt (protein kinase B), mitogen-activated protein kinases, and spleen tyrosine kinase pathways, as well as decrease the generation of reactive oxygen species to regulate platelet activation. Exogenous IL-37 injection suppressed microvascular thrombosis to protect against myocardial injury in wild-type mice but not in platelet-specific IL-1R8-deficient mice after permanent ligation of the left anterior descending coronary. Finally, a negative correlation between plasma IL-37 concentration and platelet aggregation was observed in patients with myocardial infarction. CONCLUSIONS: IL-37 directly attenuated platelet activation, thrombus formation, and myocardial injury via IL-1R8 receptor. Accumulated IL-37 in plasma inhibited platelet activation to ameliorate atherothrombosis and infarction expansion, and thus may have therapeutic advantages as potential antiplatelet drugs.


Assuntos
Infarto do Miocárdio , Trombose , Animais , Camundongos , Plaquetas/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/prevenção & controle , Infarto do Miocárdio/metabolismo , Ativação Plaquetária , Agregação Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Transdução de Sinais , Trombose/genética , Trombose/prevenção & controle
4.
Cereb Cortex ; 34(3)2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38521993

RESUMO

Alzheimer's disease (AD) and mild cognitive impairment (MCI) both show abnormal resting-state functional connectivity (rsFC) of default mode network (DMN), but it is unclear to what extent these abnormalities are shared. Therefore, we performed a comprehensive meta-analysis, including 31 MCI studies and 20 AD studies. MCI patients, compared to controls, showed decreased within-DMN rsFC in bilateral medial prefrontal cortex/anterior cingulate cortex (mPFC/ACC), precuneus/posterior cingulate cortex (PCC), right temporal lobes, and left angular gyrus and increased rsFC between DMN and left inferior temporal gyrus. AD patients, compared to controls, showed decreased rsFC within DMN in bilateral mPFC/ACC and precuneus/PCC and between DMN and left inferior occipital gyrus and increased rsFC between DMN and right dorsolateral prefrontal cortex. Conjunction analysis showed shared decreased rsFC in mPFC/ACC and precuneus/PCC. Compared to MCI, AD had decreased rsFC in left precuneus/PCC and between DMN and left inferior occipital gyrus and increased rsFC in right temporal lobes. MCI and AD share a decreased within-DMN rsFC likely underpinning episodic memory deficits and neuropsychiatric symptoms, but differ in DMN rsFC alterations likely related to impairments in other cognitive domains such as language, vision, and execution. This may throw light on neuropathological mechanisms in these two stages of dementia.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Rede de Modo Padrão , Disfunção Cognitiva/patologia , Giro do Cíngulo , Lobo Temporal/patologia , Imageamento por Ressonância Magnética , Encéfalo , Mapeamento Encefálico
5.
Proc Natl Acad Sci U S A ; 119(31): e2205469119, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35895684

RESUMO

T regulatory (Treg) cells are essential for self-tolerance whereas they are detrimental for dampening the host anti-tumor immunity. How Treg cells adapt to environmental signals to orchestrate their homeostasis and functions remains poorly understood. Here, we identified that transcription factor EB (TFEB) is induced by host nutrition deprivation or interleukin (IL)-2 in CD4+ T cells. The loss of TFEB in Treg cells leads to reduced Treg accumulation and impaired Treg function in mouse models of cancer and autoimmune disease. TFEB intrinsically regulates genes involved in Treg cell differentiation and mitochondria function while it suppresses expression of proinflammatory cytokines independently of its established roles in autophagy. This coordinated action is required for mitochondria integrity and appropriate lipid metabolism in Treg cells. These findings identify TFEB as a critical regulator for orchestrating Treg generation and function, which may contribute to the adaptive responses of T cells to local environmental cues.


Assuntos
Adaptação Fisiológica , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Mitocôndrias , Neoplasias , Linfócitos T Reguladores , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Animais , Doenças Autoimunes/imunologia , Autofagia/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/fisiologia , Modelos Animais de Doenças , Interleucina-2/metabolismo , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Neoplasias/imunologia , Linfócitos T Reguladores/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
6.
BMC Med ; 22(1): 92, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38433204

RESUMO

BACKGROUND: Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental disorders with overlapping behavioral features and genetic etiology. While brain cortical thickness (CTh) alterations have been reported in ASD and ADHD separately, the degree to which ASD and ADHD are associated with common and distinct patterns of CTh changes is unclear. METHODS: We searched PubMed, Web of Science, Embase, and Science Direct from inception to 8 December 2023 and included studies of cortical thickness comparing youth (age less than 18) with ASD or ADHD with typically developing controls (TDC). We conducted a comparative meta-analysis of vertex-based studies to identify common and distinct CTh alterations in ASD and ADHD. RESULTS: Twelve ASD datasets involving 458 individuals with ASD and 10 ADHD datasets involving 383 individuals with ADHD were included in the analysis. Compared to TDC, ASD showed increased CTh in bilateral superior frontal gyrus, left middle temporal gyrus, and right superior parietal lobule (SPL) and decreased CTh in right temporoparietal junction (TPJ). ADHD showed decreased CTh in bilateral precentral gyri, right postcentral gyrus, and right TPJ relative to TDC. Conjunction analysis showed both disorders shared reduced TPJ CTh located in default mode network (DMN). Comparative analyses indicated ASD had greater CTh in right SPL and TPJ located in dorsal attention network and thinner CTh in right TPJ located in ventral attention network than ADHD. CONCLUSIONS: These results suggest shared thinner TPJ located in DMN is an overlapping neurobiological feature of ASD and ADHD. This alteration together with SPL alterations might be related to altered biological motion processing in ASD, while abnormalities in sensorimotor systems may contribute to behavioral control problems in ADHD. The disorder-specific thinner TPJ located in disparate attention networks provides novel insight into distinct symptoms of attentional deficits associated with the two neurodevelopmental disorders. TRIAL REGISTRATION: PROSPERO CRD42022370620. Registered on November 9, 2022.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Espectro Autista , Transtornos do Neurodesenvolvimento , Humanos , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Transtorno do Espectro Autista/diagnóstico por imagem , Neurobiologia
7.
Circ Res ; 131(12): 1037-1054, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36354004

RESUMO

BACKGROUND: Vascular calcification is closely related to the all-cause mortality of cardiovascular events. Basement membrane protein nidogen-2 is a key component of the vascular extracellular matrix microenvironment and we recently found it is pivotal for the maintenance of contractile phenotype in vascular smooth muscle cells (VSMCs). However, whether nidogen-2 is involved in VSMCs osteochondrogenic transition and vascular calcification remains unclear. METHODS: VSMCs was treated with high-phosphate to study VSMC calcification in vitro. Three different mice models (5/6 nephrectomy-induced chronic renal failure, cholecalciferol-overload, and periadventitially administered with CaCl2) were used to study vascular calcification in vivo. Membrane protein interactome, coimmunoprecipitation, flow cytometric binding assay, surface plasmon resonance, G protein signaling, VSMCs calcium assays were performed to clarify the phenotype and elucidate the molecular mechanisms. RESULTS: Nidogen-2 protein levels were significantly reduced in calcified VSMCs and aortas from mice in different vascular calcification model. Nidogen-2 deficiency exacerbated high-phosphate-induced VSMC calcification, whereas the addition of purified nidogen-2 protein markedly alleviated VSMC calcification in vitro. Nidogen-2-/- mice exhibited aggravated aorta calcification compared to wild-type (WT) mice in response to 5/6 nephrectomy, cholecalciferol-overload, and CaCl2 administration. Further unbiased coimmunoprecipitation and interactome analysis of purified nidogen-2 and membrane protein in VSMCs revealed that nidogen-2 directly binds to LGR4 (leucine-rich repeat G-protein-coupled receptor 4) with KD value 26.77 nM. LGR4 deficiency in VSMCs in vitro or in vivo abolished the protective effect of nidogen-2 on vascular calcification. Of interest, nidogen-2 biased activated LGR4-Gαq-PKCα (protein kinase Cα)-AMPKα1 (AMP-activated protein kinase α1) signaling to counteract VSMCs osteogenic transition and mineralization. CONCLUSIONS: Nidogen-2 is a novel endogenous ligand of LGR4 that biased activated Gαq- PKCα-AMPKα1 signaling and inhibited vascular calcification.


Assuntos
Glicoproteínas de Membrana , Músculo Liso Vascular , Receptores Acoplados a Proteínas G , Calcificação Vascular , Animais , Camundongos , Cloreto de Cálcio , Células Cultivadas , Colecalciferol/farmacologia , Colecalciferol/metabolismo , Ligantes , Glicoproteínas de Membrana/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fosfatos/efeitos adversos , Proteína Quinase C-alfa/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Calcificação Vascular/prevenção & controle , Calcificação Vascular/genética
8.
Phys Chem Chem Phys ; 26(31): 21052-21060, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39054907

RESUMO

In this work, a mixed precursor solvent system comprising isopropyl alcohol (IPA) and 2-methoxy ethanol (MOE) is introduced for the fabrication of Cu2ZnSn(S, Se)4 (CZTSSe) thin films under ambient conditions. The effects of different IPA/(MOE + IPA) ratios on the characteristics of CZTSSe films and the corresponding devices were investigated. Our research results indicate that the addition of IPA enhances the wettability of Cu-Zn-Sn-S precursor solution on the substrate, reduces Sn loss in the film during high-temperature annealing, and diminishes band tail states. Additionally, adding IPA leads to effective enlargement of grain size, improved crystallinity, and enhanced light absorption. However, excessive content of IPA negatively impacts CZTSSe film properties and the device's performance. Notably, when substituting 20% of MOE with IPA, the short-circuit current density (JSC) increased from 30.84 mA cm-2 to 35.55 mA cm-2 in the resulting CZTSSe device, and the efficiency improved from 9.19% to 10.63%. This work provides a new method of a solvent system for preparing efficient kesterite-based solar cells.

9.
BMC Anesthesiol ; 24(1): 75, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38408901

RESUMO

OBJECTIVE: The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery. METHODS: This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation. RESULTS: The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery. CONCLUSION: This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.


Assuntos
Benzenossulfonatos , Benzodiazepinas , Hipnóticos e Sedativos , Humanos , Anestesia Epidural , Benzenossulfonatos/efeitos adversos , Benzodiazepinas/efeitos adversos , Dexmedetomidina/efeitos adversos , Hipnóticos e Sedativos/efeitos adversos , Procedimentos Ortopédicos
10.
BMC Musculoskelet Disord ; 25(1): 81, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245679

RESUMO

BACKGROUND: Symptomatic lumbar disc herniation (LDH) and lumbar isthmic spondylolisthesis (LIS) present significant challenges for military pilots, which may result in grounding if not effectively managed. Surgical treatment for LDH and LIS may offer a pathway to return to flight duty (RTFD), but recent data on this crucial topic is lacking. This study seeks to address this gap by investigating the RTFD outcomes among Chinese military pilots who have undergone lumbar spine surgery for symptomatic LDH and LIS. METHODS: A retrospective review was conducted on active-duty military pilots who underwent isolated decompressive or fusion procedures at an authorized military medical center from March 1, 2007, to March 1, 2023. The analysis utilized descriptive statistics to examine demographic, occupational, surgical, and outcome data, with a particular focus on preoperative flight status, recommended clearance by spine surgeons, and actual RTFD outcomes and time. RESULTS: Among the identified cases of active-duty military pilots with LDH or LIS treated by lumbar surgery (n = 24), 70.8% (17 of 24) consistently maintained RTFD status without encountering surgical complications or medical issues during the follow-up period. Of the seven pilots who did not RTFD, one retired within a year of surgery, two had anterior cruciate ligament injuries, three had residual radicular symptoms, and one had chronic low back pain. Excluding pilots who retired and did not RTFD for reasons unrelated to their lumbar conditions, the RTFD rate stood at 81.0% (17 of 21). The median time for recommended clearance by spine surgeons was 143.0 days (inter-quartile range, 116.5-196.0), while the median duration for actual RTFD attainment was 221.0 days (inter-quartile range, 182.0-300.0). The median follow-up post-lumbar surgery was 1.7 years (inter-quartile range, 0.4-2.9). CONCLUSION: Most military pilots diagnosed with symptomatic LDH and LIS can continue their careers and regain active-duty flight status following lumbar spine surgery, as reflected by the high RTFD rate. Lumbar spine surgery can successfully alleviate the physical constraints associated with spinal conditions, facilitating the return of military pilots to their demanding profession.


Assuntos
Deslocamento do Disco Intervertebral , Militares , Fusão Vertebral , Espondilolistese , Humanos , Deslocamento do Disco Intervertebral/epidemiologia , Deslocamento do Disco Intervertebral/cirurgia , Espondilolistese/epidemiologia , Espondilolistese/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , Vértebras Lombares/cirurgia , China/epidemiologia , Fusão Vertebral/métodos
11.
Int J Mol Sci ; 25(15)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39125955

RESUMO

BACKGROUND: Auxin, a plant hormone, plays diverse roles in the modulation of plant growth and development. The transport and signal transduction of auxin are regulated by various factors involved in shaping plant morphology and responding to external environmental conditions. The auxin signal transduction is primarily governed by the following two gene families: the auxin response factor (ARF) and auxin/indole-3-acetic acid (AUX/IAA). However, a comprehensive genomic analysis involving the expression profiles, structures, and functional features of the ARF and AUX/IAA gene families in Vaccinium bracteatum has not been carried out to date. RESULTS: Through the acquisition of genomic and expression data, coupled with an analysis using online tools, two gene family members were identified. This groundwork provides a distinguishing characterization of the chosen gene families in terms of expression, interaction, and response in the growth and development of plant fruits. In our genome-wide search of the VaARF and VaIAA genes in Vaccinium bracteatum, we identified 26 VaARF and 17 VaIAA genes. We analyzed the sequence and structural characteristics of these VaARF and VaIAA genes. We found that 26 VaARF and 17 VaIAA genes were divided into six subfamilies. Based on protein interaction predictions, VaIAA1 and VaIAA20 were designated core members of VaIAA gene families. Moreover, an analysis of expression patterns showed that 14 ARF genes and 12 IAA genes exhibited significantly varied expressions during fruit development. CONCLUSION: Two key genes, namely, VaIAA1 and VaIAA20, belonging to a gene family, play a potentially crucial role in fruit development through 26 VaARF-IAAs. This study provides a valuable reference for investigating the molecular mechanism of fruit development and lays the foundation for further research on Vaccinium bracteatum.


Assuntos
Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Família Multigênica , Proteínas de Plantas , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Filogenia , Genoma de Planta , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/genética , Vaccinium/genética , Vaccinium/metabolismo , Frutas/genética , Frutas/metabolismo , Frutas/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
BMC Nurs ; 23(1): 532, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39097692

RESUMO

PURPOSE: To investigate the prevalence of insomnia among nurses with long COVID-19, analyze the potential risk factors and establish a nomogram model. METHODS: Nurses in Ningbo, China, were recruited for this study. General demographic information and insomnia, burnout, and stress assessment scores were collected through a face-to face questionnaire survey administered at a single center from March to May 2023. We used LASSO regression to identify potential factors contributing to insomnia. Then, a nomogram was plotted based on the model chosen to visualize the results and evaluated by receiver operating characteristic curves and calibration curves. RESULTS: A total of 437 nurses were recruited. 54% of the nurses had insomnia according to the Insomnia Severity Index (ISI) score. Eleven variables, including family structure, years of work experience, relaxation time, respiratory system sequelae, nervous system sequelae, others sequelae, attitudes toward COVID-19, sleep duration before infection, previous sleep problems, stress, and job burnout, were independently associated with insomnia. The R-squared value was 0.464, and the area under the curve was 0.866. The derived nomogram showed that neurological sequelae, stress, job burnout, sleep duration before infection, and previous sleep problems contributed the most to insomnia. The calibration curves showed significant agreement between the nomogram models and actual observations. CONCLUSION: This study focused on insomnia among nurses with long COVID-19 and identified eleven risk factors related to nurses' insomnia. A nomogram model was established to illustrate and visualize these factors, which will be instrumental in future research for identifying nurses with insomnia amid pandemic normalization and may increase awareness of the health status of healthcare workers with long COVID-19.

13.
Angew Chem Int Ed Engl ; : e202408611, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38924225

RESUMO

Controlled radical copolymerizations present attractive avenues to obtain polymers with complicated compositions and sequences. In this work, we report the development of a visible-light-driven organocatalyzed controlled copolymerization of fluoroalkenes and acyclic N-vinylamides for the first time. The approach enables the on-demand synthesis of a broad scope of amide-functionalized main-chain fluoropolymers via novel fluorinated thiocarbamates, facilitating regulations over chemical compositions and alternating fractions by rationally selecting comonomer pairs and ratios. This method allows temporally controlled chain-growth by external light, and maintains high chain-end fidelity that promotes facile preparation of block sequences. Notably, the obtained F/N hybrid polymers, upon hydrolysis, afford free amino-substituted fluoropolymers versatile for post modifications toward various functionalities (e.g., amide, sulfonamide, carbamide, thiocarbamide). We further demonstrate the in situ formation of polymer networks with desirable properties as protective layers on lithium metal anodes, presenting a promising avenue for advancing lithium metal batteries.

14.
BMC Genomics ; 24(1): 24, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36647001

RESUMO

BACKGROUND: Geese exhibit relatively low reproductive performance, and follicular atresia is an important factor that restricts the egg production of geese. Systematic analysis of the regulation of follicle atresia in geese through transcriptome and proteome levels could provide meaningful information on clarifying the mechanism of follicle atresia in poultry. RESULT: The granulosa cell layer was loose, disintegrated and showed apoptosis in atretic follicles and remained intact in normal follicles. The hormone levels of FSH and LH were significantly decreased in the atresia follicles compared to the normal follicles (P < 0.05). A total of 954 differentially expressed genes (DEGs, 315 increased and 639 decreased) and 161 differentially expressed proteins (DEPs, 61 increased and 100 decreased) were obtained in atresia follicles compared to normal follicles, of which, 15 genes were differentially expressed in both transcriptome and proteome. The DEGs were mainly enriched in sodium transmembrane transport, plasma membrane, and transmembrane transporter activity based on the GO enrichment analysis and in the cell cycle pathway based on the KEGG enrichment analysis. The DEPs were mainly enriched in localization, lysosome, and phospholipid-binding based on the GO enrichment analysis. Candidate genes Smad2/3, Smad4, Annexin A1 (ANXA1), Stromelysin-1 (MMP3), Serine/threonine-protein kinase (CHK1), DNA replication licensing factor (MCM3), Cyclin-A2 (CCNA2), mitotic spindle assembly checkpoint protein (MAD2), Cyclin-dependent kinase 1 (CDK1), fibroblast growth factor 12 (FGF12), and G1/S-specific cyclin-D1 (CCND1) were possibly responsible for the regulation of atresia. CONCLUSION: The cell cycle is an important pathway for the regulation of follicular atresia. Sodium outflow and high expression of MMP3 and MMP9 could be responsible for structural destruction and apoptosis of follicular cells.


Assuntos
Atresia Folicular , Gansos , Metaloproteinase 3 da Matriz , Animais , Feminino , Apoptose/genética , Ciclo Celular/genética , Ciclinas/genética , Ciclinas/metabolismo , Atresia Folicular/genética , Gansos/genética , Células da Granulosa/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , Proteoma/metabolismo , Transcriptoma
15.
Environ Microbiol ; 25(2): 575-587, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36495168

RESUMO

Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are unique archaeal membrane-spanning lipids with 0-8 cyclopentane rings on the biphytanyl chains. The cyclization pattern of GDGTs is affected by many environmental factors, such as temperature and pH, but the underlying molecular mechanism remains elusive. Here, we find that the expression regulation of GDGT ring synthase genes grsA and grsB in thermophilic archaeon Sulfolobus acidocaldarius is temperature- and pH-dependent. Moreover, the presence of functional GrsA protein, or more likely its products cyclic GDGTs rather than the accumulation of GrsA protein itself, is required to induce grsB expression, resulting in temporal regulation of grsA and grsB expression. Our findings establish a molecular model of GDGT cyclization regulated by environment factors in a thermophilic ecosystem, which could be also relevant to that in mesophilic marine archaea. Our study will help better understand the biological basis for GDGT-based paleoclimate proxies. Archaea inhabit a wide range of terrestrial and marine environments. In response to environment fluctuations, archaea modulate their unique membrane GDGTs lipid composition with different strategies, in particular GDGTs cyclization significantly alters membrane permeability. However, the regulation details of archaeal GDGTs cyclization in response to different environmental factor changes remain unknown. We demonstrated, for the first time, thermophilic archaea orchestrate the temporal expression of GDGT ring synthases, leading to delicate control of GDGTs cyclization to respond environmental temperature and acidity stress. Our study provides insight into the regulation of archaea membrane plasticity, and the survival strategy of archaea in fluctuating environments.


Assuntos
Archaea , Ecossistema , Archaea/metabolismo , Temperatura , Glicerol/metabolismo , Lipídeos de Membrana/metabolismo
16.
J Magn Reson Imaging ; 58(1): 223-231, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36373955

RESUMO

BACKGROUND: Gradient nonlinearity (GNL) introduces spatial nonuniformity bias in apparent diffusion coefficient (ADC) measurements, especially at large offsets from the magnet isocenter. PURPOSE: To investigate the effects of GNL in abdominal ADC measurements and to develop an ADC bias correction procedure. STUDY TYPE: Retrospective. PHANTOM/POPULATION: Two homemade ultrapure water phantoms/25 patients with histologically confirmed pancreatic ductal adenocarcinoma (PDAC). FIELD STRENGTH/SEQUENCE: A 3.0 T/diffusion-weighted imaging (DWI) with single-shot echo-planar imaging sequence. ASSESSMENT: ADC bias was computed in the three orthogonal directions at different offset locations. The spatial-dependent correctors of ADC bias were generated from the ADCs of phantom 1. The ADCs were estimated before and after corrections for the phantom 1 with both the proposed approach and the theoretical GNL correction method. For the patients, ADCs were measured in abdominal tissues including left and right liver lobes, PDAC, spleen, bilateral kidneys, and bilateral paraspinal muscles. STATISTICAL TEST: Friedman tests and Wilcoxon tests. RESULTS: The ADC bias measured by phantom 1 was 9.7% and 12.6% higher in the right-left and anterior-posterior directions and 9.2% lower in the superior-inferior direction at the 150 mm offsets from the magnetic isocenter. The corrected vs. the uncorrected ADCs measurements (median: 2.20 × 10-3  mm2 /sec for both the proposed method and the theoretical GNL method vs. 2.31 × 10-3  mm2 /sec, respectively) and their relative ADC errors (0.014, 0.016, and 0.054, respectively) were lower in the phantom 1. The relative ADC errors substantially decreased after correction in the phantom 2 (median: 0.048 and -0.008, respectively). The ADCs of all the abdominal tissues were lower after correction except for the left liver lobes (P = 0.13). DATA CONCLUSION: GNL bias in abdominal ADC can be measured by a DWI phantom. The proposed correction procedure was successfully applied for the bias correction in abdominal ADC. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 1.


Assuntos
Abdome , Cavidade Abdominal , Humanos , Estudos Retrospectivos , Reprodutibilidade dos Testes , Abdome/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Imagens de Fantasmas
17.
J Surg Res ; 283: 764-770, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36470201

RESUMO

INTRODUCTION: Counseling on the immediate postoperative experience for outpatient procedures is largely based on anecdotal experience. We devised a short messaging service (SMS) survey using mobile phone text messages to evaluate real-time patient recovery following outpatient thyroid or parathyroid surgery. MATERIALS AND METHODS: Daily automated SMS surveys were sent the evening of the operation until postoperative day 10. Pain, opioid use, voice quality, and energy levels were assessed. Impaired voice and energy was defined as a score < 2/3 of normal. RESULTS: One hundred fifty five patients were enrolled with an overall response rate of 81.6%. One hundred thirty three patients had an individual response rate > 50% and were included in the final analysis. Median patient age was 60 y with 102 females (76.7%). Seventy patients (52.6%) underwent parathyroidectomy and 66 (49.6%) thyroidectomy and 10 (7.5%) neck dissection. Forty eight patients (36.1%) did not use any opioids postoperatively. Independent risk factors for higher total pain scores included thyroidectomy and patients with preoperative opioid or tobacco use, while increased opioid use was associated with age < 60 y, body mass index > 30 kg/m2, preoperative opioid or tobacco use, and history of anxiety or depression. Patients with loss of intraoperative recurrent laryngeal nerve signaling had a significantly worse overall voice score (54.65 versus 92.67, P < 0.001). Up to 10% of patients were still using opioids and/or reported impaired voice and energy levels beyond 1 wk postoperatively. CONCLUSIONS: Real-time SMS survey is an effective and potentially valuable way to monitor patient recovery following surgery. A subset of patients reported impaired voice and energy and was still using opioids beyond 1 wk after thyroid and parathyroid surgery and these patients may benefit from closer follow-up and earlier intervention.


Assuntos
Analgésicos Opioides , Glândula Tireoide , Feminino , Humanos , Tireoidectomia/efeitos adversos , Paratireoidectomia/efeitos adversos , Dor/etiologia
18.
Methods ; 207: 20-28, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36031139

RESUMO

Bladder cancer is a heterogeneous, complicated, and widespread illness with high rates of morbidity, death, and expense if not treated adequately. The accurate and exact stage of bladder cancer is fundamental for treatment choices and prognostic forecasts, as indicated by convincing evidence from randomized trials. The extraordinary capability of Deep Convolutional Neural Networks (DCNNs) to extract features is one of the primary advantages offered by these types of networks. DCNNs work well in numerous real clinical medical applications as it demands costly large-scale data annotation. However, a lack of background information hinders its effectiveness and interpretability. Clinicians identify the stage of a tumor by evaluating whether the tumor is muscle-invasive, as shown in images by the tumor's infiltration of the bladder wall. Incorporating this clinical knowledge in DCNN has the ability to enhance the performance of bladder cancer staging and bring the prediction into accordance with medical principles. Therefore, we introduce PENet, an innovative prior evidence deep neural network, for classifying MR images of bladder cancer staging in line with clinical knowledge. To do this, first, the degree to which the tumor has penetrated the bladder wall is measured to get prior distribution parameters of class probability called prior evidence. Second, we formulate the posterior distribution of class probability according to Bayesian Theorem. Last, we modify the loss function based on posterior distribution of class probability which parameters include both prior evidence and prediction evidence in the learning procedure. Our investigation reveals that the prediction error and the variance of PENet may be reduced by giving the network prior evidence that is consistent with the ground truth. Using MR image datasets, experiments show that PENet performs better than image-based DCNN algorithms for bladder cancer staging.


Assuntos
Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Teorema de Bayes , Redes Neurais de Computação , Algoritmos
19.
Mol Divers ; 27(2): 845-855, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35751771

RESUMO

A series of dihydrofuran-3-one and 9,10-phenanthrenequinone hybrid compounds were synthetized through a one-pot gold-catalyzed oxidative cyclization and Aldol-type addition cascade reaction of homopropargylic alcohols with 9,10-phenanthrenequinone. The cytotoxicity of newly synthesized compounds was evaluated in CCK8 assay against different human cancer cells, showing significantly antiproliferative activity against tested tumor cell lines with a lowest IC50 value of 0.92 µM over HCT-116. Further investigation revealed that the treatment of HCT-116 cell line with the promising compound 4c induced cell death as a selective Akt inhibitor. In addition, controlled experiments and molecular docking study suggested that the significant antitumor activity might be attributed to the unique hybrid structure, which implied the promising potential of this dual heterocycle hybrid method in the discovery of novel bioactive molecules with structural diversity.


Assuntos
Antineoplásicos , Neoplasias do Colo , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular , Proteínas Proto-Oncogênicas c-akt , Antineoplásicos/química , Proliferação de Células , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Ensaios de Seleção de Medicamentos Antitumorais , Relação Dose-Resposta a Droga , Desenho de Fármacos
20.
BMC Geriatr ; 23(1): 320, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37221471

RESUMO

BACKGROUND: Due to the increasingly aging population in China and the changes in social and family structure, older adults' care problems are becoming more and more prominent. To meet the home care needs of urban older adults, the Chinese government has launched Internet-Based Home Care Services (IBHCS). Although this model innovation can significantly relieve care problems, more and more evidence shows that there are many barriers in the process of IBHCS supply. The current literature is mostly from the perspective of the service users, and there are very few studies on the experience of service providers. METHODS: In this study, we took a qualitative phenomenological approach and used semi-structured interviews to investigate service providers' daily experiences and the barriers they encounter. A total of 34 staff from 14 Home Care Service Centers (HCSCs) were included. Interviews were transcribed and analyzed using thematic analysis. RESULTS: We identified the barriers that service providers encounter in IBHCS supply: (1) bureaucratic repression: unreasonable policy plans, harsh assessment, excessive paperwork, different preferences of government leaders, and obstacles caused by COVID-19 control lead to a shift of focus in their work; (2) profitability crisis in the market: high service costs, dampened effective demand, government intervention in setting prices, and parent companies' excessively high sales targets hinder the service supply process; (3) client-related challenges: the crisis of confidence, the dilemma of popularizing new technology, and communication barriers lead to rejection by older adults; (4) job dissatisfaction: low and unstable salary, heavy tasks, poor social acceptance of occupations, and lack of professional value reduce work enthusiasm. CONCLUSION: We have investigated the barriers faced by service providers when providing IBHCS for urban older adults in China, providing empirical evidence in the Chinese context for the relevant literature. In order to provide IBHCS better, it is necessary to improve the institutional environment and market environment, strengthen publicity and communication, target customer needs, and adjust the working conditions of front-line workers.


Assuntos
COVID-19 , Serviços de Assistência Domiciliar , Humanos , Idoso , China , Pesquisa Qualitativa , Internet
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa